1. Field of the Invention
The present invention relates to a method and associated apparatus for and/or determining antibiotic sensitivity of a paraffinophilic microorganism and, more specifically, the invention relates to expediting information regarding a more rapid and effective treatment of a patient.
2. Description of the Prior Art
It has been found that more than 80% of the acquired immunodeficiency syndrome ("AIDS") patients have MAI (Mycobactefium avium-intracellulare) present in their bodies. Wallace, J. M. and Hannah, J. B., "Mycobacterium avium Complex in Patients with Acquired Immunodeficiency Syndrome-A Clinicopathologic Study", Chest 93(5): 926-932 (1988).
Organisms of MAI prior to the AIDS epidemic were recognize as a rare form of pneumonia in patients with chronic lung infections (E. Wolinsky, Nontuberculous mycobacteria and associate diseases. Am. Rev. Respir. Dis. 1979, 119:107-59). Organisms of MAI comprise two closely relate species, M. avium and M. intracellulare, which have minor violence in the non-HIV host. By 1980, only 24 cases of MAI had been reported in the medical literature (C. R. Hotsburgh, Jr. et al., Disseminated infection with Mycobacterium avium intracellulare. Medicine (Baltimore) 1985, 64:3648). However, the epidemic of disseminated MAI infection is concurrent with the AIDS epidemic.
It has been known to test antibiotics in different concentrations against a microorganism to determine if the antibiotics will inhibit growth of the microorganism and in what antibiotic concentrations. See U.S. Pat. No. 3,826,717.
It has been known to determine drug efficacy against a paraffinophilic microorganism by confirming a lack of colony growth on a paraffin slide. See Ollar, A Modified Broth Dilution Assay for Antibiotic Sensitivity Testing of Mycobacterium Avium-intracellulare Using Paraffin Slide Cultures," Tubercle 72, pp. 198-205 (1991).
U.S. Pat. No. 5,316,918 discloses method and apparatus for determining the antibiotic sensitivity of Mycobactefium avium intracellulare (MAI) to different antimicrobial agents and dosages thereof. In this patent, a plurality of test tubes each contain an amount of an antimicrobial agent to be tested and MAI complex organisms to be assayed. A separate paraffin coated slide is placed in each test tube and incubation is effected, after which, the MAI complex organism growth on the slides at discrete time intervals is observed in order to permit determination of the minimum inhibitory concentration of the antimicrobial agent necessary to resist the MAI complex organism growth on the slides. The disclosure of this patent is incorporated herein by reference.
As will be apparent from the foregoing, it is vital to human health that MAI be treated as early as possible (C. A. Kemper et al., California Collaborative Group; Microbiologic and clinical response of patients with AIDS and MAC bacteremia to a four oral drug regimen; In: Program and abstracts of the 30th Interscience Conference on Antimicrobial Agents and Chemotherapy; Atlanta, Oct. 21-24, 1990; Washington D.C.; Am. Society for Microbiology; 1990; 297. abstract).
While the foregoing systems have made major advances in respect of antibiotic sensitivity testing, there remains a substantial need for methods and apparatus for enhancing a degree of automation and the resultant speed of processing specimens in order to determine the antibiotic sensitivity of paraffinophilic organisms in order to facilitate more rapid and effective treatment of patients.
There is a real and substantial need for improved means of rapidly determining the antibiotic sensitivity of MAI and other paraffinophilic organisms.